Introduction:

To find the leverage (or Mechanical Advantage) of a lever, you must start by measuring the lever arms. To make this measurement, you must master the vocabulary of levers!

Activity:

• Complete the A2 worksheet (duplicated in the section labeled Practice), dealing with the vocabulary of levers.

Conclusion:

• Can you describe a lever using the formal terms in our vocabulary list?
• Can you explain what Archimedes meant when he said, "Give me a lever long enough and a fulcrum on which to place it, and I shall move the world."

Practice:

• Foundation

• Mastery

The paragraph below was taken from the Wikipedia article on Levers. The eight boxes cover up words that appear in the word bank above. Not every word in the Word Bank is used, and some words are used more than once! See if you can complete the paragraph so it makes sense again!

• A first-class lever is a lever in which the A_ is located between the input effort and the output B_. When you use a first-class lever, you apply a C_ (by pulling or pushing) to one side of the bar, which causes the lever to rotate about the D_, lifting the E_ on the opposite side. If the F_ that you are pushing on is larger than the _G lifting the load, you can have a large H_.

• Expertise

Can you figure out how to describe a second- and third-class lever?

Enrichment: